Learning the syntax of a language can be achieved fairly quickly for most languages.
Learning the implications of that syntax takes a lot longer (C++ is a good example here, otherwise "Effective C++" and "More Effective C++" would have been unnecessary).
Learning the libraries and tools associated with a language can be an effectively unlimited task.
So I don't agree. It's better to hire a good programmer than a mediocre one, sure, but given two programmers of somewhat comparable quality the one with more experience often proves to be considerably more valuable than the other. This is doubly true if one of them has experience in the specific tools that you will be using on the project.
The closer fitting user will have been through a lot of the debugging/learning/understanding processes that the other has still to encounter. Even the finest programmer has to learn to work with the occasional WTFs of libraries.